Digital cameras that make use of imaging elements have become very popular in recent years. With digital camera, there has been a need not only for a greater number of pixels in the imaging elements, but also for higher performance of the lens barrel, which forms an optical image on the imaging elements. More specifically, there is a need for a lens barrel equipped with a higher-power zoom lens system.
Meanwhile, in the field of digital camera, the main body needs to be made smaller in order to make the product more portable. There is therefore a need for a more compact imaging device equipped with a lens barrel and an imaging element, which should contribute greatly to the goal of obtaining a smaller main body. To reduce the size of an imaging device, a so-called bending optical system has been proposed in which the optical path is bent along the zoom lens system (see Patent Citations 1 to 4, for example).
Patent Citation 1: Japanese Patent No. 3,925,457
Patent Citation 2: Japanese Laid-Open Patent Application 2007-17957
Patent Citation 3: Japanese Laid-Open Patent Application 2007-271649
Patent Citation 4: Japanese Laid-Open Patent Application 2005-351932